A Digital Signal Processing Based Detection Circuit for Short-Circuit Protection of SiC MOSFET

A short-circuit detection (SCD) circuit is proposed for power electronics systems that use silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). The proposed SCD circuit incorporates a digital circuit for processing the voltage induced at the parasitic inductance of the source of SiC MOSFET to obtain an improved stable turn-off operation of the SiC MOSFET under SC condition. Compared with that of the conventional analog signal processing based SCD circuits, the proposed circuit has the advantages of having a turn-off operation which is robust to process, voltage, and temperature variations, being fully integrated without the use of external components and ease of design. The proposed circuit was implemented in a 350-nm Bipolar-CMOS-DMOS process. For functional verification, an SC test board integrating the proposed SCD circuit was developed. Experimental result validates that the proposed SCD circuit effectively functions under SC condition.